Neven Mrgan’s about labeling the back button:
The title of the entire bar is the title of this view; the Back button shows the previous, parent viewâ€™s title. Here, then, is a piece of advice for app designers: The Back button should never show the text â€œBackâ€.
This is redundant and it provides no context. Note that Apple never does this, not in any app. Instead, they provide either the full title of the previous view, or an abbreviated/truncated version of it.
And this is part of the reason why the “Back” button on every Android phone is utterly confusing at times.